package top;
use Moose::Role;
requires	'token';
sub foo {
    print "foo\n";
}

sub useful_method{
   print "I'm useful\n"
}

package bottom;
use Moose::Role;
with 'top';

override 'foo' => sub {
    print "bar\n";
};

package something;
use Moose;
with "bottom";

sub token {
    print "implement me in the concrete class";
}

package main;
my $something = new something;
$something->foo;